Pericardial reinforcement device

ABSTRACT

The following relates to catheter-based devices, systems, and methods for minimally-invasively delivering an inflatable pericardial support into the pericardial space of a mammalian myocardium. The devices and systems include extending and positioning plural support members through a catheter into the pericardial space and then positioning the inflatable member on the epicardial surface of the myocardium. Once positioned, fluid can be delivered to the inflatable member to provide a confining pressure to the myocardium.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/788,366 filed Apr. 19, 2007 which claims priority to U.S. ProvisionalApplication No. 60/793,085 filed Apr. 19, 2006 entitled, PERICARDIALREINFORCEMENT DEVICE. The applications are hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to devices, systems, and methods fordelivering a pericardial reinforcement device onto the epicardium of amammalian myocardium, more particularly, to devices, systems, andmethods for minimally-invasively delivering an inflatable pericardial“sail” into the pericardial space for attachment to the myocardium.

For many patients suffering from, e.g., cardiomyopathy, progressivedilation of the left ventricle of the cardial muscle, i.e., the heart,can precede an end-stage disease. Dilation renders the heart lessefficient as it struggles to maintain contractile function. Moreover,the mechanical burden of adverse remodeling is thought to increase wallstress and, further, to impair cardiac function. This is particularlyproblematic when dealing with the left ventricle, which is the heart'spump.

The medical world has sought with some success to treat cardial dilationwith medication. However, many of the medications include undesirableside effects. As a result, medications do not offer a long-term solutionfor all patients.

In recent years, those skilled in the art have sought mechanical meansto prevent or constrict dilation. For example, the CorCap CardiacSupport Device™ manufactured by Acorn Cardiovascular, Inc. ofMinnetonka, Minn. was the subject of a study published in December 2004.The study reported the results of 48 patients who, as part of open-heartsurgery, underwent an invasive implantation of a restrictive, mesh-likedevice, which was wrapped around the patients' hearts to slow leftventricle dilation. The findings of the study suggest that, by applyinga restrictive mechanical force around the heart, adverse left ventricleremodeling in patients with cardiomyoplasty can be stabilized and,possibly, can be reversed. One shortcoming of the CorCap and similardevices is the invasive nature of the procedure.

Therefore, it would be desirable to provide alternative minimallyinvasive, systems that will reduce risk and improve recovery time.

SUMMARY OF THE INVENTION

The present invention discloses a minimally-invasive cardiac treatmentdevice. The device includes support elements that are positionable inthe pericardial space about a mammalian myocardium and an inflatablemember that is coupled to and movable along the support elements from afirst position to a deployed position.

In a preferred embodiment of the invention, the support element includesan actuator such as a pulley or spindle section with which all actuatingmechanism can be used to position the inflatable member. The device canalso include a slotted portion through which the inflatable member cantravel.

The device further includes a fluid infusion port for filling theinflatable member with a fluid and/or a pouch for adjusting fluidpressure in the inflatable member.

A minimally-invasive system for cardiac treatment is also disclosed. Thesystem includes a catheter for entering a mammalian pericardium; aplurality of support members (or “masts”)that are extendable from thelumen of the catheter into pericardial space about the myocardium; andan inflatable member (or “sail”) coupled to and movable along thesupport members.

The system further includes a rod or tube member for advancing theinflatable member through the catheter and for positioning the memberbetween adjacent support members, a detaching mechanism that detachesthe support member from the rod, a filling tube for filling theinflatable member with a fluid, and/or a pouch for adjusting fluidpressure in the inflatable member after the detaching mechanism hasdetached the plurality of mast portions from the detachable rod member.

The present invention also provides a method of treating a mammalianmyocardium having progressive dilation, e.g., of a left ventriclethereof. Preferably, the method includes surgically introducing acatheter device into a mammalian pericardium which can be done through asub-xyphoid or optical entry point; introducing and positioning pluralsupport members into the pericardial space with the catheter device;positioning an inflatable member between adjacent support members, e.g.,by pulling a line through a pulley or spindle portion disposed in thesupport member or by pushing the inflatable member between adjacentsupport members using a rod member or tube; and introducing a fluid intothe inflatable member to apply pressure to the myocardium. A fluid canalso be inserted into the pericardial space to distend adjacent tissuesand thereby aid in the extension of the support members into thepericardium.

Optionally, the method further comprises detaching the inflatablemembers and the support members from the delivery rod or tube memberand/or adjusting fluid pressure in the inflatable member. The procedurecan be performed under fluoroscopic and/or echo-cardiographics guidance.Hemodynamic monitoring can be used to confirm location and operation ofthe device.

A further embodiment of the invention employs an implant that can beinserted from an insertion device using rods that are directed intoposition by the user in a single stage insertion process. The inflatablemember is inserted through a distal opening of the insertion device froma folded delivery configuration to an unfolded or deployedconfiguration. The inflatable member has a plurality of inflatablesections each having a fluid port that can be connected directly to oneor more reservoirs or to a single reservoir with a switching manifold.

The implantable system can include a pump and control system that isprogrammable for each patient and can include sensors for feedbackcontrol or pacing leads or conductive elements to control pacing of theheart. This control system can be incorporated into 20 an implanthousing that is sized to fit in the abdominal cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings in which like reference characters refer tothe same parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 provides a diagram of a system and device for providingminimally-invasive pericardial confinement according to the presentinvention;

FIG. 2 provides a flow chart of a method for providingminimally-invasive pericardial confinement according to the presentinvention;

FIG. 3 shows illustratively the step of extending the “masts” inaccordance with the present invention;

FIG. 4 shows illustratively the step of “hoisting the sails” inaccordance with the present invention;

FIG. 5 shows illustratively an alternative for “hoisting the sails”using an internal pulley and pulling mechanism in accordance with thepresent invention;

FIG. 6 shows illustratively a pressure measuring device for monitoring,measuring, and adjusting the pressure level in the sails in accordancewith the present invention;

FIG. 7 shows illustratively the step of inflating or deflating the sailsin accordance with the present invention; and

FIG. 8 shows illustratively the step of removing the catheter and mastsand attaching a pouch to the filling tube for further pressuremonitoring in accordance with the present invention.

FIG. 9 shows an embodiment of a pericardial reinforcement device in thedeployed, inflated configuration within the pericardium and surroundingthe ventricles of the heart.

FIGS. 10A-10G show a series of sectional views of embodiments of apericardial reinforcement device in the deployed and inflatedconfiguration depicting optional inner wall profiles of the device. FIG.10A shows a device that has uniform contact and uniform pressure(arrows) over the left ventricle. FIG. 10B shows a device thatconcentrates increased inward pressure (arrow) against a portion of theleft ventricle (LV). FIG. 10C is a schematic representation of thedevice shown in FIG. 10A. FIG. 10D is a schematic representation of thedevice shown in FIG. 10B. FIG. 10E is a schematic representation of adevice having a ribbed inner wall. FIG. 10F is a schematicrepresentation of a device having a ribbed inner wall and a collar atthe top end for retention. FIG. 10G depicts schematically a devicehaving a separately inflatable outer chamber.

FIGS. 11A-11E show a series of sectional views representing anembodiment of a single-stage non-invasive deployment process of apericardial reinforcement device using a catheter-based approach. FIG.11A depicts a catheter pre-loaded with an inflatable sail attached tosupport elements. FIG. 11B shows a cross-section through the loadedcatheter of FIG. 11A. FIG. 11C shows the catheter system with apericardial reinforcement device partially deployed around the apex ofthe heart. FIG. 11D shows the catheter system with the sail fullyextended from the catheter and deployed in position around the heart.FIG. 11E shows the retraction of the support elements back into thecatheter and the fully deployed pericardial reinforcement device, readyfor inflation.

FIGS. 12A-12I show a series of sectional views representing anembodiment of a two-stage non-invasive deployment process of apericardial reinforcement device using a catheter-based approach. FIG.12A depicts a catheter pre-loaded with support elements and aninflatable sail attached to rod elements. FIG. 12B is a cross-sectionthrough the upper portion of the catheter containing the sails and rodelements. FIG. 12C is a cross-section through the lower portion of thecatheter containing the support elements. FIG. 12D is a close-up view ofone embodiment of the linkage between a rod element of the uppercatheter section and a support element of the lower catheter section.FIG. 12E shows the catheter system with partially deployed supportelements. FIG. 12F shows the catheter system with the support elementsfully extended from the catheter and in position around the heart. FIG.12G shows the system with partially deployed sail being positioned alongthe pre-positioned support elements by pushing on the rod elements usingthe uppermost portion of the catheter. FIG. 12H shows the system withsail fully extended along the support elements. FIG. 12I depicts thecatheter system having the reinforcement device in position and inflatedand released from the rod elements; the rod elements and supportelements have been partially retracted. In an alternative embodiment(not shown), the individual support elements can be extended andretracted separately, e.g., one at a time, to aid in positioning thecatheter system for deployment of the sails.

FIG. 13A depicts the use of a splaying mechanism built into the catheterfor extending and positioning the support elements around the apex ofthe heart. FIGS. 13B and 13C illustrates the use of an angularconstriction at the distal end of the catheter to splay the supportelements.

FIG. 14A schematically depicts an embodiment of the pericardialreinforcement device having guide tubes mounted onto the outer wall ofthe sail to accommodate support elements and/or rod elements. FIG. 14Bdepicts an embodiment of the device having rails mounted onto the outerwall of the sail to accommodate support elements and/or rod elements.

FIGS. 15A-15J schematically illustrate the use of lines or rod elementsto deploy the inflatable sails of a pericardial reinforcement device. InFIG. 15A, a line bound to an attachment site at the top end of aninflatable sail runs through the lumen of a support element, back downthrough a guide tube attached to the sail, and continues out through thecatheter. FIG. 15B depicts how the line from FIG. 15A, after exiting theproximal end of the catheter (not shown) can be manipulated by thesurgeon to deploy the sail. In FIG. 15C, the sail has been raised intoposition and the positioning line has been detached from the sail. FIG.15D shows how the positioning line and support element are removed fromthe installed pericardial reinforcement device. FIG. 15E shows thesupport element fully removed and the sail ready for inflation. Analternative embodiment is shown in FIG. 15F, in which the supportelement has been pre-positioned around the heart, and a rod element isinserted into the guide tube. In FIG. 15G, the rod element of FIG. 15Fis pushed to extend the sail out of the catheter and along the supportelement into position around the heart. In this embodiment, the guidetube encloses the support element as the device is moved into position.FIG. 15H shows the pericardial reinforcement device in deployedposition. In FIG. 15I, the support element and rod element have beenretracted from the guide tube. In FIG. 15J the support element and rodelement have been fully removed and the pericardial reinforcement deviceis in fully deployed and ready for inflation.

FIG. 16A is an external view of an intercostal approach to access thepericardial space using a catheter device of the invention. FIG. 16Bshows a cross-sectional view of the approach in FIG. 16A.

FIGS. 17A-17G present a series of schematic illustrations of anembodiment of a process of deployment of a pericardial reinforcementdevice. FIG. 17A shows the placement of a blunt-tip needle into thepericardial space at the apex of the heart. In FIG. 17B, the needle hasbeen exchanged for a catheter, and a guidewire is advanced into thepericardial space. In FIG. 17C, a catheter device containing apericardial reinforcement device is inserted along the guidewire. FIG.17D shows the support elements extended from the catheter and positionedaround the heart. In FIG. 17E, the pericardial reinforcement device isdeployed in position around the heart. FIG. 17F shows the introductionof fluid into the sails of the pericardial reinforcement device. FIG.17G depicts the fully inflated and deployed pericardial reinforcementdevice and the withdrawn catheter device.

FIG. 18A shows an embodiment of a deployed pericardial reinforcementdevice having a fill tube attached to a fluid reservoir through acontrol unit containing a pump. The control unit and reservoir areimplanted in the abdomen. FIG. 18B shows an embodiment of a pericardialreinforcement device with a fill tube attached to an infusion portimplanted in the chest.

FIG. 19A shows a cross-section of a deployed and inflated pericardialreinforcement device surrounding the heart. This embodiment has a singleinflatable chamber. FIG. 19B shows an embodiment of a pericardialreinforcement device that exerts increased pressure at a selectedlocation on the left ventricular wall (arrow). This embodiment has asingle inflatable chamber, but exerts differential inward pressure basedon its geometry. FIG. 19C shows an embodiment of a pericardialreinforcement device having four inflatable chambers, each fitted with aseparate fill line for differential application of inwardly directedpressure. Use of greater fill pressure in the chamber adjacent to theleft ventricle is used to apply selectively greater pressure to thatarea.

FIG. 20 depicts an embodiment of a control unit used to adjust theinward pressure of the pericardial reinforcement device against theheart.

DETAILED DESCRIPTION OF THE INVENTION

The present invention describes devices, systems, and methods forminimally-invasively delivering a pericardial reinforcing device intothe pericardial space about a mammalian myocardium, i.e., heart, and,more particularly, to devices, systems, and methods forminimally-invasively delivering an inflatable, pericardial “sail” intothe pericardial space; wrapping the “sail” around some portion of themyocardium; and inflating the “sail” to apply a confining pressure tothe myocardium.

For convenience, the devices and systems of the present invention willbe described in the context of their use in the medical process shown inFIG. 2. FIG. 2 provides a flow chart of a method forminimally-invasively delivering an inflatable, pericardial “sail” intothe pericardial space; for wrapping the “sail” around some portion ofthe myocardium; and for inflating the “sail” to apply a confiningpressure to the myocardium. Those skilled in the art will be familiarwith standard or routine medical procedures for use in conjunction withthe present invention.

Referring to FIGS. 1 and 2, in a first step, a catheter 10 is introducedinto the pericardial space, or pericardium, about the myocardium (STEP1). The pericardium can be entered using a sub-xyphoid approach or,alternatively, an apical approach. The introduction procedure can beperformed using fluoroscopic and/or echocardiographic guidance toposition the distal end, i.e., the internal end, of the catheter 10 at adesired location within the pericardium. Confirmation of the location ofthe distal end of the catheter 10 within the pericardium can beperformed hemodynamically.

The catheter 10 includes a proximal end, which remains external of themammalian subject or patient during the procedure, and an internal,distal end. The catheter 10 is tubular in shape and includes an outerportion 12 and an inner portion, or lumen 14. The outer portion 12 canbe made of a flexible but axially stiff, plastic material, such as thosematerials typically used for manufacturing catheters for cardiaccatheterization.

Structured and arranged inside or within the lumen 14 of the catheter 10are a plurality of extendable support elements 16 a, 16 b, and 16 c, or“masts”. The masts are substantially low profile and can include anouter portion 11 and an inner portion, or inner passage 13. The mastscan also be made of a flexible but axially stiff, plastic material. Theends of the masts or outer surface 11, which may contact the epicardialsurface, are soft to prevent damaging or scarring the same. Preferably,there are at least three masts 16 a, 16 b, and 16 c inside the catheter10.

Structured and arranged inside or within the inner passage 13 of eachmast 16 a, 16 b, and 16 c is a positionable and detachable rod elementabout which is configured, e.g., fixedly attached, an inflatable member15 a, 15 b, and 15 c, or “sail”. Rod elements 18 a, 18 b, and 18 c canalso be made of a flexible, plastic material. The sails can be made fromsoft, flexible materials, such as are used for pulmonary artery balloonsor silicone breast implants.

Referring to FIG. 3, after the catheter 10 is introduced and positionedwithin the pericardium (STEP 1), the masts can be extended from thedistal end of the catheter 10 into the pericardial space (STEP 2). Eachmast is separately movable, so that the masts can be positioned wheredesired. To facilitate extension of the masts 16 a, 16 b, and 16 c inthe pericardium (STEP 2), the outer surface of the outer portion 11 ofthe masts can be pre-lubricated and/or small amounts of fluid can beintroduced into the pericardium through open space in the lumen 14and/or through a fluid conduit 19 provided in the lumen 14 for thatpurpose.

Referring to FIG. 4, after the masts are extended and positioned aboutthe myocardium (STEP 2), the sails 15 a, 15 b, 15 c are “unfurled” andmoved from a first position stored within the catheter to a deployedposition on the epicardium (STEP 3).

In one aspect of the invention, rod elements 18 a, 18 b, and 18 c areused to position the sails. More specifically, a coupler such as a railportion 17 can be structured and arranged on the peripheral surface 21of the outer portion 11 of member 16 a. Rod element 18 a can bestructured and arranged to include a groove 23 that is operationallyassociated with and linearly translatable along the rail portion 17 ofmember 16 a. Alternatively, a groove 22 can be structured and arrangedwithin the inner peripheral surface 21 of the outer portion 11 of member16 b. Rod element 18 b can be structured and arranged to include a railportion or guide 25 that is operationally associated with and linearlytranslatable in the groove 22 of member 16 b. In yet anotheralternative, the rod member 18 c is free to move relative to member 16 cor can have coupler 41.

Once the masts have been positioned about the myocardium (STEP 2)properly and where desired, the rod elements are forcibly advanced alongthe rail portion 17, in the groove 22, pulling the sail as the rodelement advances (STEP 3).

Referring to FIG. 5, in another aspect of the invention, instead ofusing rod elements 18 a, 18 b, and 18 c to position the sails on theepicardium (STEP 3), the sails can be “hoisted” using a small pulleydevice 23, or spindle, that can be structured and arranged at or nearthe distal end of the mast. More specifically, a pulling mechanism 24,e.g., wire, string, thread, filament, and the like, can be releasablyattached to the sail. The free-running end of the pulling mechanism 24can be routed about the pulley device 23 and, then, out the proximal endof the catheter 10. Applying a pulling or tugging force T to thefree-running end of the pulling mechanism 24 causes the sail to beraised, or “hoisted”, up the mast. The pulley device 23 can bestructured and arranged so that the sails can be hoisted from outsidethe masts or, alternatively, can be hoisted from within the innerpassage 13 of the masts.

Referring to FIGS. 6 and 7, once the sails have been positioned aboutthe myocardium (STEP 3), fluid, e.g., compressed air, gas, liquids, andthe like, can be introduced into the inflatable sails, e.g., via afilling tube 27, to provide a desired confining pressure (STEP 4), e.g.,to the left ventricle. Preferably, a device for measuring the fluidpressure 28 in the sails, e.g., a pressure gauge, pressure meter,pulmonary artery catheter, and the like, is in operational associationwith the filling tube 27, to measure and to monitor the pressure exertedon the myocardium (STEP 5). Accordingly, when the pressure inside thesails is too high or not high enough, the sails can be deflated orinflated, respectively, to achieve a desired confining pressure.

In yet another aspect of the present invention, each inflatable member15 a, 15 b, and 15 c disposed between adjacent support elements 16 a, 16b, and 16 c, respectively, is separately inflated and controllable.Consequently, the confining pressures on different portions of themyocardium that are covered by different portions of the sail, can bevaried as necessary or desired. Accordingly, when there are threeinflatable members 15 a, 15 b and 15 c, the filling tube 27 can includethree separate fluid conduits, each in operational association with adiscrete inflatable member 15 a, 15 b or 15 c and each being monitored adedicated pressure gauge 28 (STEP 5).

Once the pressure in the sails is at a desired level (STEP 5), thecatheter 10, detachable rods, and any other portions of the system thatwill not remain internalized in the mammalian subject can be removed(STEP 6), leaving the masts and inflated sails in place. The catheter 10and rod members 18 a, 18 b, and 18 c are structured and arranged toeasily detach from the masts and sails and the catheter to be easilyremoved from the incision.

In still another aspect of the invention, the filling tube 27 remainsinternalized, to provide means for monitoring, measuring, and adjustingthe fluid pressure in the sails for as long as necessary. Referring toFIG. 8, the filling tube 27 is in operational association with aninfusion port 28 that is external to the mammalian subject. A pouch 29that contains the external portion of the filling tube 27 and theinfusion port 28 can be attached to the filling tube 27 at or near thexyphoid or apical point of entry.

FIG. 9 shows a fully installed pericardial reinforcement device fittedaround the ventricles of the heart and positioned within the pericardium45. The device is positioned with the continuous distal edge 54 of theinflated member approximately aligned at the A-V junction, or near thetop of the ventricles. Distal edge 54 optionally can be reinforced witha stiffening structure such as a wire or band of metal, plastic, orfabric. Distal edge 54 also can take the form of a seam or weld joint inthe sail materials, e.g., where the materials are glued or sewntogether. In this embodiment, guide tubes 52 are present on the exteriorsurface of the sails. In the embodiment shown, an attachment site 50 ispresent near the top end of each guide tube. The guide tubes 52 wereused to align the inflatable member with support elements, rod elements,or lines during deployment of the device. The support elements, rodelements, or lines can be attached to the inflatable member atattachment sites 50. Typically, one support element, rod element, orline is reversibly attached at each attachment site. After the desiredfinal placement of the device is achieved, then the support elements,rod elements, or lines are detached from the attachment sites andretracted back into the catheter, either before, during, or afterinflation of the inflatable members. Depending on the chosen deploymentmethod, either support elements, rod elements, lines, or combinations ofthese may be used to position the pericardial reinforcement device,although generally only one type of structure will be attached at theattachment sites (e.g., support elements and rod elements are usedtogether for deployment, but only the rod elements are attached to theattachment sites).

Referring to FIGS. 10A-10G, a variety of textures or structural profilescan be used on the inner surface of the inflatable members that are incontact with the heart. The device shown in FIG. 10A, and depictedschematically in FIG. 10C, has a smooth texture, which provides evenlydistributed force where the inflated device contacts the heart.Alternatively, a greater inwardly directed constraining force can befocused over a chosen area, such as all or a portion of the leftventricle, by the use of a pressure point or area 58 as shown in FIG.10B and depicted schematically in FIG. 10D. Pressure point or area 58 isa protrusion of the inner wall of the inflatable member which resultsfrom the geometry of the inner wall material. When inflated, such apressure point results in greater pressure at its point of contact withthe heart than the pressure produced by the surrounding portion of theinflatable member that lacks such a protrusion. The size and shape ofone or more pressure points 58 can be chosen as desired to achieve thedesired shape and intensity of the zone of applied inward pressure.Optionally, the pressure point can be accompanied by, e.g., surroundedby, a corresponding outwardly deflecting profile in the region of theinflatable member surrounding the pressure point, to provide a zone of aselected pressure surrounded by a zone of lower pressure, or zeropressure. One or more such zones of selectively applied pressure can beemployed to define one or more selective treatment areas. For example,treatment can be selectively applied to regions of the myocardiumdamaged by a previous ischemic event or infarction. Alternatively, zonesof lower or zero inward pressure can be selectively applied toterritories supplied by one or more chosen coronary arteries, such asthe left anterior descending artery, or to an aneurism.

FIG. 10E illustrates a ribbed design, which can be used to facilitateretention of the device in the original deployment position. The ribscan be aligned horizontally to prevent downward migration of the device,or the ribs can be aligned vertically to prevent twisting or rotation ofthe device. A desired combination of horizontal, vertical, and/ordiagonal ribs can be used. The ribs can be formed by designing the innerwall of the inflatable member to produce small protrusions wheninflated. Alternatively, structures such as wires, bands, seams, rails,hooks, or barbs can be added to the inner surface of the inflatablemember which contacts the epicardium, or embedded within the inner wallmaterial, a seam, or a pocket between the inner and outer walls. Asshown in FIG. 10F, a collar structure 56 can be formed, e.g., at or nearthe top of the inflatable member, in order to hold the device in placeand to resist downward migration towards the apex of the heart. A collar56 can be formed from a ring-shaped pressure point that surrounds theheart, e.g., at or near the A-V junction, or near the top of theventricles. Alternatively, such a collar can be formed from segments,interrupted for example by welds, joints, or seams between inflatableelements of the device. The collar 56 can also be constructed from oneor more separately inflatable elements, so that collar pressure can beseparately regulated. Collar 56 can also be formed from structuralmaterial, such as a wire, band, rail, or seam added to the exteriorsurface of the inner wall of the device.

The magnitude of inwardly directed pressure in a pericardialreinforcement device can be from about 1 to about 10 mm Hg, or fromabout 3 to about 8 mm Hg, or from about 1 to about 8 mm Hg. Preferably,the inward pressure is about 3 mm Hg. The magnitude of the inwardpressure at a pressure point can exceed the inward pressure of theoverall device or of the area surrounding the pressure of the device byabout 1, 2, 3, 4, or 5 mm Hg, or more.

A percutaneous access device such as a tubular probe or catheter systemfor non-invasive deployment of a pericardial reinforcement deviceaccording to the invention can be configured in a variety of differentways, e.g., depending on the desired method of deployment. In oneembodiment, the device is deployed by using 3 or more rod elements,preferably 4, that are attached directly to one or more inflatablemembers via attachment sites.

Referring to FIGS. 11A-11E, one such “single stage” tubular assemblycontains a guidewire tube 30 along its central axis. The device isinserted into the pericardial space by inserting the proximal end ofpreviously implanted guidewire 31 into guidewire tube 30 and sliding thetube or catheter along the guidewire, through an intercostal orsub-xyphoid incision, and into the pericardial space below the apex ofthe heart. FIG. 11A depicts the pre-loaded catheter traveling alongguidewire 31. The catheter assembly has a proximal section 90, which canbe a plunger, and a distal section 92 that contains the pericardialreinforcement device prepackaged for deployment.

In FIG. 11B, which shows a cross-section of the distal section, four rodelements 18 are evenly spaced around guidewire tube 30, and one or moreinflatable members 15 are appropriately folded and distributed aroundthe support elements. Preferably, each inflatable member 15, or theentire inflatable assembly, is folded into a pleated pattern similar tothat of a paper fan, so as to fit the inflatable members into thecatheter and promote an orderly and even unfolding upon extension outthe distal end of the catheter and beneath the apex of the heart. Otherfold patterns also can be used. Preferably, the folds of the inflatablemembers are radially distributed in a spiral pattern, such as thepinwheel or whirlpool pattern shown in FIG. 11B. This type of patternpromotes compact loading and smooth deployment of the inflatablemembers.

Each inflatable member has an inner wall, that faces toward theepicardium when deployed, and an outer wall, that faces the pericardiumwhen deployed. Suitable materials for the outer wall of an inflatablemember include non-compliant materials such as polyethyleneterephthalate (PET). Compliant materials such as a polyamide material(nylon) or polyvinyl chloride (PVC) can be used for either the inner orouter walls of an inflatable member.

The sites of attachment 50 of the rod elements to the inflatable memberscan be positioned near the distal ends of rod elements 18. The distalends of rod elements 18 are preferably fitted with ball-shaped,spherical, or ellipsoidal structures to avoid damage to the heart andother tissues during deployment and positioning. Alternatively, the rodelement material can be bent back and away from the heart.

Simultaneous deployment of the rod elements 18 and the inflatablemembers 15 can be achieved, for example, by the surgeon moving aplunger, a lever, or another structure at the proximal end of thecatheter, or attached to a control handle at the distal end of thecatheter. In the embodiment depicted in FIG. 11C, pushing on the plungerat the proximal end of the catheter results in the rod elementsextending outward from the distal end of the catheter. The rod elementssimultaneously push the inflatable members, via the attachment sites,out the distal end of the catheter as well. As the pleated fold of theinflatable members unfolds, it causes the inflatable assembly to openand assume a roughly conical shape which allows it to pass over the apexof the heart. As the plunger is pushed, the rod elements continue tomove up and around the heart, and continue to extract and unfurl theinflatable members, which move upwards towards the base of the heart. InFIG. 11D, the rod elements are fully extended, and the inflatablemembers have been fully extracted from the distal end of the catheter ortube and moved into position around the ventricles of the heart. Ifnecessary, the surgeon can manipulate the catheter at this time in orderto position the uninflated inflatable members around the heart. Forexample the catheter can be moved from side-to-side, slid into thepatient, partially withdrawn from the patient, or rotated to achieve theoptimum position. Fluoroscopic guidance during the deployment of thedevice is preferable. To facilitate this, the device optionally can beoutfitted with x-ray opaque markings

After the device is brought into the appropriate position around theheart, the attachment mechanism at the distal end of the rod elements18, which bind the rod elements to the attachment sites 50 on theinflatable members 15, can be released. For example, a twisting motionof the catheter handle or plunger, or the activation of a button orlever on a catheter control handle can be used to release the rodelements from the attachment sites. Once the rod elements have beenuncoupled from the inflatable members, the rod elements are withdrawninto the catheter and the catheter is removed from the subject. Theinflatable assembly is then inflated by infusion of fluid to the desiredpressure (FIG. 11E).

In another embodiment, the device is deployed using a “two stage”approach. For this approach, a group of 3 or more support elements,preferably 4, are deployed around the heart during the first stage. Inthis case, the support elements are not attached to the inflatablemembers. During the second stage, the inflatable members are pushed orraised into position around the heart using the previously placedsupport elements as guides or tracks, or as a glide surface. In eithercase, the two-stage approach takes advantage of the support elements tophysically uncouple the deployment of the pericardial reinforcementdevice from the surface of the beating heart during the first phase.Later, once the device is in position, i.e., during the second phase,the device is coupled to the heart by inflation in the absence of thesupport elements. The two-stage deployment method is shown in FIGS.12A-12I.

FIG. 12A shows a pre-loaded catheter assembly for a two-stage deploymentof a pericardial reinforcement device according to the invention.Similar to the single-stage catheter assembly, an axial guidewire tube31 accommodates a guidewire to facilitate the insertion of the catheterinto the pericardial space. The two-stage catheter or rigid tubularassembly has a proximal section 94, or plunger, a middle section 96, anda distal section 98. FIG. 12B shows a cross-section of the middlesection. In this embodiment, the middle section contains four rodelements 18 disposed around the central guidewire tube 30. Each rodelement is reversibly attached to an attachment site on an inflatablemember that is packed within the middle section of the catheter. Theinflatable members are folded and distributed as described above for thedistal portion of the single stage catheter assembly. FIG. 12C shows across-section of the distal section of a two-stage catheter assembly. Inthe embodiment shown, the distal section contains an axial guidewiretube 30, around which are disposed four support elements 16. The supportelements 16 are of similar length as the rod elements 18, or slightlyshorter than the rod elements in certain embodiments. In someembodiments, the support elements 16 are aligned with, and attached to,the rod elements 18 at the junction between the distal and middlesections of the catheter assembly. In other embodiments, supportelements 18 are not coupled to rod elements 18. In such embodiments, thesupport elements merely form a convenient glide surface or guide, whichcovers the surface of the heart and against which the device can bedeployed.

FIG. 12D illustrates the detail of an attachment mechanism that allowsthe rod elements 18, by means of rail portion 25, to slide up a track orgroove 22 in the support elements 16. Rail portion 25 is linearlytranslatable in groove 22, such that pushing on a plunger attached torod elements 18 advances the rods 18 toward the distal ends of supportelements 16, thereby deploying the attached inflatable members 15. Aninflatable member 15 is attached to rod element 18 by, for example, thecoupling of an attachment site 50 (a small ring in the embodiment shown)to rod spike 18 d. Other arrangements are possible. Advantages of thearrangement depicted in FIG. 12D include: (1) positive displacement ofthe inflatable members along the support elements by a simple push rodmechanism; (2) distribution of deployment forces according to thedistribution of support elements; (3) uncoupling of the deployment ofinflatable members from the structural dynamics of the beating heart bythe use of previously deployed support elements; (4) automaticuncoupling of rod elements 18 from support elements 16 by pushing therods off the track at the distal end of the support elements; and (5)automatic uncoupling of rod elements 18 from inflatable members 15 byretracting the rod elements back towards the catheter.

Once the two-stage catheter assembly is in place at the apex of theheart, support elements 16 are extended out from the distal end of thecatheter assembly. In the embodiment shown in FIG. 12E, this can beaccomplished by sliding the middle section of the catheter assembly intothe distal section. After support elements 16 are fully extended and inposition around the ventricles (FIG. 12F), the first stage is completed.The second stage is initiated by advancing the rod elements withattached deflated inflatable members 15 (FIG. 12G). As was the case forthe single stage approach, the advancement of the rod elements causesthe inflatable members to exit the distal end of the catheter andunfold, thereby forming an approximately cone-shaped structure thatsurrounds the heart (FIG. 12H). The support elements 16 and rod elements18 are retracted into the catheter by sliding back the middle section,the catheter assembly is removed from the subject, and then theinflatable members are inflated with fluid (FIG. 12I). In otherembodiments, the inflation process can be carried out before or duringretraction of the rod and support elements.

In a variation of the two-stage process, a set of support elements 16 isadvanced into the pericardial space individually rather than as a unit.This can offer flexibility in positioning the support elements around abeating heart. In order to permit this option, an embodiment of thetwo-stage catheter assembly is used that permits extension of eachsupport element separately. One example of how to accomplish this is bysplitting the structure in which the support elements are mounted, andcoupling each support element mounting structure separately to a movableportion of the catheter assembly, or to separate controls in a cathetercontrol handle.

It is instrumental when deploying either support elements or rodelements from a catheter assembly according to the invention to spreador splay the elements so as to accommodate the shape of the heart. Onemechanism for splaying such elements is depicted in FIGS. 13A and 13B.By incorporating wedge-shaped forming element 80 at the exit point atthe catheter distal end, an appropriate material will be induced tosplay when either a rod element or a support element is advanced out ofthe catheter. Suitable materials include fine metal wires and plasticsthat can be bent to yield an angular rod-like structure. The support orrod element can be shaped so as to form an angle at the wedge shapedforming element but retain a straight orientation thereafter. Oneembodiment with this characteristic is a partially rounded flat surfacethat folds inwardly more easily than it folds outwardly. The edges ofthe curved cross-sectional profile of the rod or support element canpoint away from the central axis of the catheter, such that the rod orsupport element will bend outward at the wedge-shaped forming element,but will resist bending inward, much like the action of a metal tapemeasure having a similar curved cross-sectional profile. The splay angleof support elements or rod elements as they exit the catheter andapproach the heart can be tailored to the size and shape of therecipient heart, or varied as the support elements or rod elementsprogress upwards along the heart, e.g., to maintain optimum contact.This can be accomplished, e.g., by adjusting the forming wedge at thedistal end of the catheter. A control mechanism can be included in thecatheter that alters the angle or position of the forming wedge. Forexample, by tilting the wedge, or by displacing it towards or away fromthe exiting rod or support elements, the splay angle can be increased ordecreased as desired, either before or during deployment. An alternativeto splaying the rod or support elements as they exit the catheter is touse pre-formed rod and/or support elements that are compressed into thecatheter and assume their pre-formed shape upon exiting from thecatheter. Yet another alternative is to use a combination of pre-formedrod and/or support elements whose form is modified upon exit from thecatheter using a forming element.

Either single-stage or two-stage deployment of a pericardialreinforcement device can be assisted by adding certain structures to theoutside of the inflatable members, or alternatively having structuresrun through the inflatable members. Two examples are shown in FIGS. 14Aand 14B. The embodiment of FIG. 14A includes guide tubes 52, which canserve to align a rod element 18 (push rod), a line 24 (pull line), or asupport element 16 with attachment sites 50 on an inflatable member, andalso can maintain an uninflated inflatable member in alignment with arod element 18, a line 24, or a support element 16, and at some distancefrom the beating heart, so that the inflatable member does not becomeentangled or exert too great a drag on the beating heart when beingpositioned. FIG. 14B shows a rail as an alternative guide structure.Such a rail can couple to a track or groove in a support element 16 or arod element 18.

The use of guide tubes is illustrated in FIGS. 15A-15J. In FIGS.15A-15E, guide tubes 52 are used together with pull lines 24 to directthe positioning of inflatable member 15. In this embodiment, supportelement 16 is hollow, permitting line 24 to be routed through supportelement 16, around a pulley 23 or spindle at the distal end of supportelement 16, and back down through guide tube 52 and out the proximal endof the catheter (FIG. 15A). When line 24 is pulled through or out of thecatheter in a proximal direction, inflatable member 15 is hoisted oversupport element 16 (FIG. 15B) and out to its distal end (FIG. 15C).Support element 16 is then withdrawn from the guide tube (FIG. 15D),leaving inflatable member 15, with attached guide tube 52, in positionaround the heart (FIG. 15E).

FIGS. 15F through' 15J illustrate an embodiment employing rod elementsinstead of lines. Rod element 18 is initially positioned withinsail-mounted guide tube 52 (FIG. 15F). The guide tube is then slid oversupport element 16, which was previously positioned around the heart(FIG. 15G), until inflatable member 15 is fully inserted to the distalend of support element 16 (FIG. 15H). Rod element 18 and support element16 are then withdrawn, together (FIG. 15I), leaving inflatable member inposition around the heart, ready for inflation (FIG. 15J).

FIG. 16 displays a two-stage catheter embodiment in position at the apexof the heart, prior to extension of the support elements. FIG. 16A showsa front view, using a left intercostal approach, and FIG. 1613 shows across-sectional view.

FIGS. 17A-17G provide an overview of deployment of a pericardialreinforcement device using a two-stage catheter assembly. Percutaneousaccess of the pericardial space can be performed either via a subxyphoidapproach or in the apical position (4th intercostal mid clavicularspace) at 45 degrees to the patient (see Laham et al., Clin Cardiol(1999) 22:16-9; Laham et al., Catheter Cardiovasc Intery (1999)47:109-111; and Laham et al., Catheter Cardiovasc Intery (2003)58:375-381, each of which is incorporated herein by reference). This canbe accomplished, for example using a Tuohy 17 epidural needle withcontinuous contrast and saline injection. The needle is attached to apressure manifold and a 10 cc syringe via a three-way stopcock. Inaddition, the needle is attached to an EKG monitoring lead. The needleis advanced slowly with diluted contrast instillation. Onceintrapericardial location is confirmed, a wire is advanced over which a10 French sheath is introduced into the pericardial space (FIG. 17B).Following the use of a dilator to enlarge the passageway, the catheterassembly is inserted into position (FIG. 17C) with its distal end belowthe apex of the heart.

Alternatively, a 5 cm incision can be made in the fourth intercostalspace (left thoracotomy) and the procedure as well as the deviceplacement can be performed under thoracoscopic direct vision. Briefly,the patient is intubated into the right main stem bronchus and the leftlung is deflated. 10-mm “camera” thoracoport (U.S. Surgical Corporation,Norwalk, Conn.) is inserted in the 4th intercostal space midaxillaryline. A 30-degree thoracoscope (Stryker Corporation, Stryker Endoscopy,San Jose, Calif.) is introduced through this port into the chest. Underdirect visualization, a 5-mm port is inserted in the eighth intercostalspace anterior axillary line. After placing the port, the trochar isremoved to allow the introduction of both endoscopic shears and grasper.A pericardial window is made in a longitudinal fashion, exposing a largesection of left ventricular myocardium. A port for device insertion isplaced directly superior to the apex of the heart, lateral to thesternum and left internal mammary artery. See Thompson et al. (2004) AnnThorac Surg 78:303-7.

After the catheter is in place near the heart, the support elements areextended (FIG. 17D), and then the inflatable members are extended alongthe support elements into position around the ventricles of the heart(FIG. 17E). Fluid is introduced into the inflatable members (FIG. 17F),and the pressure adjusted to apply the desired operating inwardpressure. FIG. 17F illustrates an embodiment in which a fluid line runsthrough the catheter lumen and is attached to one or more fill lines onthe inflatable members. After the device is finally installed andadjusted, the catheter is removed and the incision is closed (FIG. 17G).

Adjustments to the confining pressure provided by the pericardialreinforcement device can be made following surgical implantation of thedevice. FIG. 18 demonstrates two embodiments of the device that includestructures for adjusting the pressure by adding or removing fluid fromone or more inflatable chambers. In FIG. 18A, the fill line from theinflatable member or members is connected to pump 62 which in turn isconnected by tubing to fluid reservoir 29. The pump and fluid reservoircan be implanted within the abdomen and connected via a subcutaneousline to the pericardial reinforcement device in the chest. A simplerversion is shown in FIG. 18B, having a subcutaneous infusion portconnected to the fill line. Fluid can be withdrawn or added through theinfusion port using a needle to lower or raise the confining pressure,respectively.

The force exerted on the heart by the device and vice versa can beobtained from a plot of ventricular wall force vs. displacement(stress-strain curve), the slope of which is a function of theproperties of the material that the inflatable members are made of, andthe degree of inflation. The stress/strain relationship is representedby S_(r)=Pd/2t and S₁=pd/4t, where P=left ventricular end diastolicpressure (LVEDP), d=ventricular diameter, t=ventricular wall thickness,S_(r)=hoop or radial stress, and S₁=axial or longitudinal stress.

From the above equation, the calculated radial tensile strength (TS) ofa balloon can be calculated as follows: TS=pd/2t where p=burst pressure,d=diameter (as made), and t=thickness (as made). The pressure exertedinwardly can be adjusted to the strain and outward deformation of theepicardium. Measurement of the epicardial deformation during the cardiaccycle has been previously described (Arts and Raneman, 1980). At itsmaximum diameter, the filled ventricle in diastole will exert under 5pounds of force on the constraining device, which is within the linearportion of the stress-strain curve (see Walsh, R, (2005) Heart FailureReviews 10:101-7). Displacement will be maximum in diastole and minimumin systole. The transmural pressure exerted by the device would be equalto the difference between LVEDP and the pressure exerted by the device(typically 10 mm Hg=15 mm Hg−5 mm Hg). Thus, in a preferred embodiment,on average the device would exert 5 mm Hg of pressure at end-diastole.This can be adjusted based on LVEDP sensed (e.g. by a pulmonary arterialcatheter). In the experiments performed by Ghanta et al. (Circulation115:1201-10 (2007)), the optimal restraint level was determined to be 3mm Hg in an ovine heart failure model, which allowed for a reduction intransmural pressure that produced improved cardiac mechanics withoutreduction in aortic pressure or cardiac output.

FIG. 19 demonstrates three embodiments which differ in the applicationof pressure to the ventricular wall. In FIG. 19A, a single inflatablemember 15 surrounds the heart, with approximately uniform contact anduniform pressure from all sides. In FIG. 19B, elevated inward pressure(arrow) is selectively applied to a portion of the left ventricle (LV)by means of a single inflatable member containing a pressure point,i.e., a point of contact with the ventricular wall surrounded by aregion lacking contact. The embodiment shown in FIG. 19C has fourseparate inflatable members, each of which can be adjusted independentlyof the others by variable filling to obtain a desired pressure.

The inner wall of an inflatable member is flexible and compliant inorder to accommodate the dynamic form of a beating heart, and also toaccommodate long term changes in size or shape of the heart, e.g., dueto progression of cardiac hypertrophy. The outer wall of an inflatablemember can be either flexible or inflexible and compliant ornon-compliant. Preferably, the outer wall is flexible and compliant.More preferably, the outer wall is less compliant than the inner wall.Differential compliance or elasticity between the inner and outer wallscan be advantageous in allowing the inflated device to absorb shapechanges during the cardiac cycle without fully transmitting thosechanges outwardly to the pericardium. This can improve the stability ofdevice placement over time without offering too much resistance tomovement of the heart. Maintaining some compliance in the outer wallfurther permits the device to expand over time, e.g., by adding fillfluid, in order to respond to disease progression, with less increase ininward pressure than would result from a non-compliant outer wall. Insome embodiments, the relative compliance of the outer and inner wallsis adjusted to the needs of the individual patient. For example, apatient with early stage hypertrophy might be fitted with a devicehaving a more compliant outer wall to accommodate more long termexpansion. Both the absolute and the relative compliance of the outerand inner walls also can be varied over the surface of an inflatablemember or an assembly of inflatable members to produce differentialeffects, e.g., different inward pressures, at different regions of theventricular myocardium.

One embodiment of a pericardial reinforcement device includes anon-compliant outer layer surrounding the inflatable member or assemblyof inflatable members. Such an outer layer can be formed, for example,by adding a separately inflatable outer chamber 70 (FIG. 10G) coveringthe inflatable inner chamber (inflatable member 15). Once the device isin place around the heart, a polymerizable fluid can be introduced intothe outer chamber and allowed to polymerize, forming a non-compliantouter layer. The inner inflatable member or members can be inflatedeither before, during, or after inflation of the outer chamber.

Two or more inflatable members can be joined to form an inflatableassembly. The arrangement of inflatable members within an assembly caninclude either vertical or horizontal patterns, or other patterns, ofindividual inflatable members that are joined side-by-side throughnon-inflatable joints, seams, or welds. Preferred embodiments use avertical arrangement of inflatable members, i.e., with seams betweenadjacent inflatable members running vertically, approximating a linefrom the apical region of the heart to the basal region. The pattern of“banding” or arrangement of individual inflatable members in an assemblycan be chosen to affect a desired pattern of force on the heart. If agiven inflatable member is designed without a pressure point, i.e., hasuniform contact with the epicardium after inflation, then the forceacross the contact surface for that inflatable member is expected to berelatively uniform. However, the force exerted by different inflatablemembers can be different, particularly if their contact profiles and/orfill pressures are different. Thus, by joining inflatable members in agiven pattern, a desired force pattern can be applied to the heart.Further, in certain embodiments the pericardial reinforcement device canbe individually tailored to match the size, shape, or pathology of therecipient heart. This can be accomplished, for example, by preparing athree-dimensional model of the patient's heart using CT scans or MRI,and then assembling precursor components, i.e., inflatable members ofdifferent size and shape, into a custom-fitted device. This can be doneto assure optimum or uniform pressure application to the patient's heartas well as more stable placement and a better treatment outcome.

A method of designing a constraint device can include using individualpatient heart data or averaged patient class data to construct aparticular device configuration for a particular patient. This caninvolve determining the size and shape of an individual's heart, such asby collecting image data of the heart from one or more imagingmodalities (e.g., ultrasound image, magnetic resonance image, x-ray orCT image, etc.) and using this data to select a particular constraintdevice configuration or to program the system controller to controlseparate inflatable regions to conform to the needs of a particularindividual.

For embodiments of the pericardial reinforcement device that employadjustable confining pressure, it can be useful to surgically implant,e.g., in the abdomen, a control unit such as the one displayed in FIG.20. A control unit either can be controlled from external instruments toadjust the confining pressure, or can be designed to automaticallyadjust the pressure without intervention. In control unit 60, fill line27 from the pericardial reinforcement device is connected through pump62 to fluid reservoir 29. Pump 62 is controlled by the components oncircuit board 64, including processor 65, memory 67, and communicationport 66. The electronic components are fed by battery 68. Lead 69 fromone or more pressure sensors embedded within the inflatable members isconnected to the circuit board and the processor. The communicationsport can contain a wireless transmitter and/or receiver to permitresetting pressure parameters or reprogramming from an external deviceand for the transmission of sensor or other stored data from thereinforcement device. An optional feature is manifold 75, which can becontrolled by the processor to direct fluid flow to or from a selectedinflatable section of the restraint device, using manifold outlet lines76 a, 76 b, or 76 c, each of which is connected to a separate inflatablemember.

While the invention is described through the above-described exemplaryembodiments, it will be understood by those of ordinary skill in the artthat modifications to, and variations of, the illustrated embodimentsmay be made without departing from the inventive concepts disclosedherein. Accordingly, the invention should not be viewed as limited,except by the scope and spirit of the appended claims.

1. A cardiac treatment device comprising: a support element that can be positioned in a pericardial space for placement about a pericardial surface of a mammalian myocardium; and an inflatable member that moves relative to the support element from a first position to a deployed position.
 2. The device of claim 1 wherein the support element includes an actuating member about which a actuator can be used to position the inflatable member.
 3. The device of claim 1 wherein a plurality of support elements include a coupler along which the inflatable member can be forcibly advanced by pushing or pulling.
 4. The device of claim 1 wherein the device further comprises a fluid infusion port for filling the inflatable member with a fluid.
 5. The device of claim 1 wherein the device further comprises a pouch in fluid communication with the inflatable member through a channel for adjusting fluid pressure in the inflatable member.
 6. The device of claim 1 wherein the inflatable member comprises separate sections attached to adjacent support members.
 7. The device of claim 1 wherein the inflatable member has separately inflatable sections such that different confining pressures can be applied to different portions of an epicardial surface.
 8. The device of claim 8 further comprising a sensor that measures fluid pressure in the inflatable member.
 9. The device of claim 1 further comprising a plurality of sensors attached to the inflatable member.
 10. The device of claim 1 further comprising one or more conductive elements attached to a surface of the inflatable member.
 11. The device of claim 10 further comprising a controller electrically connected to the one or more conductive elements.
 12. The device of claim 11 wherein the controller generates pacing signals delivered to myocardial tissue with the one or more conductive elements.
 13. The device of claim 1 further comprising a peripheral cavity such that the inflatable member is positioned between the cavity and a surface of the myocardium.
 14. The device of claim 13 wherein the peripheral cavity extends entirely around a circumference of the myocardium.
 15. The device of claim 1 wherein the first position comprises a folded configuration.
 16. The device of claim 15 wherein the folded configuration comprises a plurality of folds extending circumferally about an axis.
 17. The device of claim 13 further comprising a port in fluid communication with the peripheral cavity such that a material can be inserted into the cavity to form a rigid outer wall.
 18. The device of claim 2 wherein the actuating member comprises one or more rods that are coupled to the support element and to a distal end of the inflatable member.
 19. The device of claim 2 wherein the actuating member is releasable from the support element and the inflatable member.
 20. The device of claim 7 wherein the separately inflatable sections have separate fluid ports. 21-77. (canceled) 